KR20160031089A - Spindle crack monitoring system and spindle process of manufacture - Google Patents

Abstract

The present invention relates to a monitoring system to detect a crack on a shaft, and a method to manufacture the shaft. The monitoring system to detect the crack on the shaft comprises: a detection shaft which performs a role of a rotation shaft or a role of a fixing shaft supporting a rotation body; a nitrogen injection path formed in the detection shaft to inject nitrogen into the detection shaft; an input port combined with an inlet of the nitrogen injection path; a wireless detection sensor combined with an outlet of the nitrogen injection path, detecting and transmitting nitrogen pressure in the nitrogen injection path; and a display unit receiving a signal detected in the wireless detection sensor and displaying the signal. As such, the wireless detection sensor detects a crack and transmits the signal to the display unit when the crack is generated in the detection shaft. The signal transmitted to the display unit is digitized and displayed such that a change in value of the pressure can be checked; thereby the crack of the detection shaft is able to wirelessly be monitored such that there is no need for an additional connection hose or wiring. As such, a facility is able to be very simplified, and the detection shaft is able to be used as both the fixing shaft and the rotation shaft.

Description

Technical Field [0001] The present invention relates to a spindle crack monitoring system and a spindle process manufacturing method,

The present invention relates to an axial crack detection monitoring system and a shaft manufacturing method, and more particularly, to a method and apparatus for monitoring the degree of cracking of a sensing axis by wirelessly, filling a plurality of nitrogen injection passages with nitrogen through a single input port, The present invention relates to an axial crack detection monitoring system and a shaft manufacturing method capable of precisely detecting the entire region of a sensing axis with a single display unit as well as an operation of forming a nitrogen injection passage and connecting the plurality of nitrogen injection passages to each other. will be.

Recent rotary machines are in the trend of high efficiency, high reliability, and high speed and light weight. Accordingly, there is an increasing need to detect and cope with excessive vibrations that may occur during operation in a timely manner. Particularly, when the rotating body of the rotating machine is excessively cracked due to excessive cracking, there is a danger that it will be momentarily disastrous.

In addition, the design and operating conditions of many rotary machines are designed to withstand harsh stress conditions and environments. Repeated large torsional and axial loads result in the motion of complex rotators and finally mechanical fatigue that can cause cracks. Therefore, the early detection of the crack origin occurring in the rotating body is very important because it can prevent various types of disasters due to crack propagation through maintenance and replacement at an appropriate time.

In addition, the system for finding such a crack is a high speed rotating body with a great risk when the rotating body is broken due to cracking, a crane system capable of causing a large financial loss when the operation is stopped suddenly, a power plant and a large compressor It is an essential element.

Korean Patent No. 10-0682514

In order to solve the above problems, the present invention provides an axis crack detection monitoring system and a shaft manufacturing method that can wirelessly monitor the degree of cracking of a sensing axis.

It is still another object of the present invention to provide an axial crack detection monitoring system and a shaft manufacturing method that can fill nitrogen into a plurality of nitrogen injection passages with one input port.

It is another object of the present invention to provide an axial crack detection monitoring system and a shaft manufacturing method that can simplify the operation of forming the nitrogen injection passage and the operation of connecting the plurality of nitrogen injection passages to each other.

It is still another object of the present invention to provide an axis crack detection monitoring system and a shaft manufacturing method capable of precisely detecting the entire sensing axis with a single display unit.

In order to accomplish the above object, according to the present invention, there is provided an axis crack detection and monitoring system comprising: a sensing shaft installed in an equipment and serving as a rotating shaft that receives external power and rotates or supports a rotating body; A nitrogen injection passage formed in the sensing axis so as to inject nitrogen into the sensing axis; An input port coupled to an inlet of the nitrogen injection passage; A nitrogen injector injecting nitrogen into the nitrogen injection path through the input port; A wireless sensor coupled to the outlet of the nitrogen injection passage for sensing and transmitting a nitrogen pressure in the nitrogen injection passage; And a display unit receiving and displaying a signal detected by the wireless sensor.

Another feature of the axial crack detection monitoring system of the present invention is that the nitrogen injection passage is formed with a plurality of passages in the sensing axis, the plurality of passages being connected together by a connecting passage, Nitrogen is injected into the nitrogen injection path, and both ends of the penetrating connection path are closed with a finishing member.

Another feature of the axial crack detection monitoring system of the present invention is that the nitrogen injection passage is formed to have a plurality of passages in the sensing axis, each of the passages being formed to have a separate space, And an inlet port and a check valve are provided at the inlet of each of the plurality of nitrogen injection passages, respectively, and wireless sensors are respectively installed at the outlets of the plurality of nitrogen injection passages. In the display portion, Each of the display windows is provided to separately display the pneumatic pressure, the pneumatic pressure in the plurality of nitrogen injection passages is measured by each of the wireless sensors, and then transmitted to the display unit to be individually displayed on the respective display windows. So as to confirm the change of the pressure for each nitrogen injection path of the gas.

Another feature of the axial crack detection monitoring system of the present invention is that the nitrogen injection passage is formed so as to penetrate from one end to the other end along the longitudinal direction of the sensing shaft, and a male screw portion is formed at the other end of the sensing shaft; And a nitrogen induction cap having a female threaded portion to be fastened to a male thread portion of the sensing shaft. An air chamber is formed in the nitrogen induction cap so that a plurality of nitrogen injection passages are connected to each other.

According to another aspect of the present invention, there is provided a shaft manufacturing method for an axial crack detection and monitoring system, comprising: an injection path forming step of forming a plurality of nitrogen injection paths along a longitudinal direction of a sensing shaft installed in an equipment; A connection passage processing step of penetrating the detection shaft along its lateral direction so that a plurality of nitrogen injection passages are connected to each other; And a finishing step of finishing both ends of the connection passage with a finishing member so that all the passages except the inlet and the outlet of the nitrogen injection passage form a sealed passage connected together.

As described above, according to the present invention, there is provided a method of controlling an internal combustion engine comprising a sensing shaft serving as a rotary shaft or a fixed shaft for supporting a rotating body, a nitrogen injection passage formed in the sensing shaft so as to inject nitrogen into the sensing shaft, And a display unit coupled to the outlet of the nitrogen injection passage for sensing and transmitting nitrogen pressure in the nitrogen injection passage to receive and display a signal sensed by the wireless sensor. Therefore, when a crack occurs in the sensing axis, the wireless sensor senses the signal and transmits it to the display unit, and the signal transmitted to the display unit is numerically displayed and thus the change value of the pressure can be confirmed. Therefore, since the degree of cracking of the sensing axis can be monitored wirelessly, no separate connection hose or wiring is required, and thus the facility becomes very simple. In addition, the sensing axis can be used not only as a fixed axis but also as a rotary axis.

The present invention is characterized in that a plurality of nitrogen injection passages are formed along a longitudinal direction of a sensing shaft installed in the equipment and a plurality of nitrogen injection passages are connected to each other by passing a connection passage along a lateral direction of the detection shaft, The ends of the passage are closed with a closing member so that all the passages except for the inlet and the outlet of the nitrogen injection passage form a sealed passage connected together. Therefore, the operation of forming the nitrogen injection passages and the operation of connecting the plurality of the nitrogen injection passages to each other are very simple and quick, so that workability and productivity are greatly improved.

Since the plurality of nitrogen injection passages are all connected by the connection passage, the present invention can fill the plurality of nitrogen injection passages with nitrogen by one input port, so that the nitrogen filling operation is very simple and quick, Productivity is greatly improved.

The nitrogen injection passage of the present invention is formed so as to penetrate along the longitudinal direction from one end to the other end of the sensing shaft. A nitrogen induction cap having an air chamber formed therein is coupled to one end of the sensing shaft, and a plurality of nitrogen injection passages Respectively. Thus, when the nitrogen injection passages are formed in the sensing axis and the nitrogen-inducing cap is fastened to the end of the sensing axis, a plurality of nitrogen injection passages are connected at the same time. Therefore, it is very easy to connect the nitrogen injection passages and thus the productivity of the detection shaft is greatly improved.

A plurality of nitrogen injection passages are formed in the sensing axis of the present invention. A wireless sensor is provided at each of the plurality of nitrogen injection passages. The display unit is provided with a plurality of nitrogen injection passages Display windows are installed. Therefore, the pneumatic pressures in the plurality of nitrogen injection passages are respectively measured by the respective wireless sensors, and then transmitted to the display unit so as to be individually displayed in the respective display windows, so that the change in pressure can be confirmed for each of the plurality of nitrogen injection passages . Therefore, it is possible to easily monitor which portion of the sensing axis causes cracks, multiple cracks, and the degree of cracks on a single display unit, so that the entire detection axis can be precisely diagnosed.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram of an axial crack detection monitoring system of the present invention.
2 is a partially cutaway perspective view showing a first embodiment of a sensing shaft according to the present invention.
3 is a partially cutaway perspective view showing a second embodiment of the sensing axis of the present invention.
Figure 4 is a schematic front cross-
5 is a partially cutaway perspective view showing a third embodiment of the sensing axis of the present invention.
Figure 6 is a schematic front cross-
7 is a partially cutaway perspective view showing a fourth embodiment of the sensing axis of the present invention.
8 is a flowchart sequentially showing the manufacturing method of the sensing axis

FIG. 1 is a schematic view showing an axial crack detection monitoring system of the present invention, and FIG. 2 is a partially cutaway perspective view showing a first embodiment of a sensing axis according to the present invention.

This axis crack monitoring and monitoring system of the present invention includes a sensing axis 10, a nitrogen injection passage 12, an input port 22, a nitrogen injector 26, a wireless sensor 28, .

The sensing shaft 10 is installed in the equipment and serves as a rotating shaft that receives external power to be rotated, serves as a fixed shaft for supporting the rotating body, or serves as a supporting shaft for supporting the equipment.

The nitrogen injection passage 12 is formed in the sensing shaft 10 so that nitrogen can be injected into the sensing shaft 10. The nitrogen injection passage 12 is elongated along the longitudinal direction of the sensing shaft 10 and extends from one end of the sensing shaft 10 to the other end thereof.

The input port 22 is coupled to the inlet 13 of the nitrogen injection passage 12. A check valve 24 is coupled between the inlet port 22 and the inlet 13 of the nitrogen injection passage 12. Therefore, the nitrogen injected into the nitrogen injection passage 12 from the input port 22 is not backwashed.

The nitrogen injector 26 injects nitrogen into the nitrogen injection passageway 12 through the input port 22.

This nitrogen injector 26 is a nitrogen charging gun that connects the hose 27 of the nitrogen injector 26 to the input port and injects the compressed air of the air compressor through the conversion filter (not shown) And then supplied through the hose 27. [

The nitrogen injector 26 is easy to carry and can be used at any time in an atmosphere. In particular, since the diameter of the nitrogen injection passage 12 of the sensing shaft 10 is not large, a large amount of nitrogen is not required. Therefore, only a small-capacity nitrogen injector 26 is sufficient.

The radio detection sensor 28 is coupled to the outlet 14 of the nitrogen injection passage 12 to sense and transmit the nitrogen pressure in the nitrogen injection passage 12. [ The radio detection sensor 28 may be provided on the side of the outlet 14 after connecting the plurality of nitrogen injection passages 12 with the connection passage 16 or may be provided separately for each of the plurality of nitrogen injection passages 12 .

The display unit 30 receives the signal sensed by the wireless sensor 28 and displays the signal. The display unit 30 includes a receiver (not shown) for detecting a signal of the wireless sensor 28. A display window 32 is provided to convert the received signal and digitize and display the received signal. .

The axis crack detection and monitoring system of the present invention having such a configuration first manufactures the sensing axis 10 and injects nitrogen into the manufactured sensing axis 10. [

The sensing shaft 10 is manufactured in the following manner. A plurality of nitrogen injection passages 12 are formed along the longitudinal direction on the sensing shaft 10 installed in the equipment.

A check valve 24 is provided at the inlet 13 of the nitrogen injection passage 12 and the check valve 24 is coupled to the input port 22. [ And at the outlet 14 of the nitrogen injection passage 12, a wireless sensor 28 is installed.

When the nitrogen injector 26 is operated after the hose 27 of the nitrogen injector 26 is connected to the input port 22, the nitrogen is injected into the nitrogen injection passageway 12 through the input port 22 and the check valve 24 Nitrogen is injected.

The nitrogen injector 26 is a device for injecting nitrogen only by filtering nitrogen in compressed air of an air compressor. Such a nitrogen injector 26 can be suitably used for the sensing shaft 10 which is suited to a small amount of nitrogen injection as in the present invention. When the nitrogen injector 26 is used, it is small in size, easy to carry, and requires no separate communication, so that it can be easily carried and used without being limited by the space.

The axis crack monitoring system of the present invention has the following advantages.

The present invention relates to an apparatus and a method for controlling a rotation of a rotary shaft of a rotary shaft of a rotary shaft An inlet port 22 coupled to the inlet 13 of the nitrogen inlet passage 12 and an outlet port 14 connected to the outlet 14 of the nitrogen inlet passage 12 to sense the nitrogen pressure in the nitrogen inlet passage 12 And a display unit 30 that receives and displays a signal sensed by the wireless sensor 28. The wireless sensor 28 may be a wireless sensor,

Therefore, when a crack occurs in the sensing shaft 10, the wireless sensor 28 senses the signal and transmits the signal to the display unit 30, and the signal transmitted to the display unit 30 is digitized and displayed. .

Therefore, since the degree of cracking of the sensing shaft 10 can be monitored wirelessly, no separate connection hose or wiring is required and thus the facility is very simple. In addition to the case where the sensing shaft 10 is a fixed shaft, .

FIG. 3 is a partially cutaway perspective view showing a second embodiment of the sensing shaft 10 of the present invention, FIG. 4 is a schematic frontal sectional view of FIG. 3, and FIG. 8 is a flowchart sequentially showing a manufacturing method of the sensing shaft 10 .

The present invention relates to a control apparatus for an internal combustion engine, which comprises a detection shaft (10) installed in an equipment and serving as a rotating shaft that receives external power and rotates, a supporting shaft for supporting the rotating body, An inlet port 22 connected to the inlet 13 of the nitrogen injection passage 12 and an inlet port 22 connected to the inlet 13 of the nitrogen injection passage 12. The nitrogen injection passage 12 is formed in the detection shaft 10 so that nitrogen can be injected into the nitrogen injection passage 10, And a radio detection sensor 28 coupled to the outlet 14 of the nitrogen injection passage 12 for sensing and transmitting the nitrogen pressure in the nitrogen injection passage 12.

Here, the nitrogen injection passage 12 is formed to have two passages in the sensing shaft 10, and these passages are connected together by the connection passage 16 to form a plurality of The nitrogen injection passageway 12 is filled with nitrogen. Both ends of the penetrating connecting passage (16) are closed with a closing member (18). The closure member 18 may be a closed seal or may be a screw.

The inlet port 22 and the check valve 24 are coupled to the inlet 13 of one of the two nitrogen injection passages 12 and the other one of the nitrogen injection passages 12 14, a wireless sensor 28 is provided.

The present invention with such a configuration is characterized in that when nitrogen is injected through the input port 22, nitrogen is filled in the entirety of the two nitrogen injection passages 12 through the connection passage 16. [

In the present invention as described above, the operation of connecting the plurality of nitrogen injection passages 12 to each other is very simple and quick. That is, holes are formed in the transverse direction on the sensing shaft 10 to form the connecting passages 16. And a plurality of nitrogen injection passages 12 formed in the longitudinal direction of the sensing shaft 10 are connected to each other by the connecting passage 16.

Therefore, it is possible to connect the plurality of nitrogen injection passages 12 by a relatively simple operation of forming the connecting passage in the lateral direction on the sensing shaft 10, so that the workability and productivity of the sensing shaft 10 are greatly improved.

Further, since the plurality of nitrogen injection passages 12 are all connected by the connection passage 16, the present invention can fill the plurality of nitrogen injection passages 12 with nitrogen through one input port 22, Nitrogen filling operation is very simple and fast, and thus the productivity of the sensing shaft 10 is greatly improved.

The sensing shaft 10 of the present invention is manufactured by the following method.

First, an injection passage processing step (S10) is performed in which a plurality of nitrogen injection passages (12) are formed along the longitudinal direction on a sensing shaft (10) installed in the equipment.

When the nitrogen injection passages 12 are formed in the sensing shaft 10, a connection passage process is performed so that the plurality of nitrogen injection passages 12 are connected to each other through the connection passages 16 along the lateral direction of the sensing shaft 10 Step S20.

When the connecting passage 16 is formed, the connecting passage 16 is closed at both ends with a closing member 18 so that all the passages except the inlet 13 and the outlet 14 of the nitrogen injection passage 12 are connected together And a closing step (S30) for forming a sealed passage.

FIG. 5 is a partially cutaway perspective view showing a third embodiment of the sensing shaft 10 of the present invention, and FIG. 6 is a schematic frontal sectional view of FIG.

According to the present invention, there is provided an axis crack detection and monitoring system comprising: a sensor shaft installed in an equipment and serving as a rotating shaft that receives external power to be rotated, a fixed shaft supporting the rotating body, A nitrogen injection passage 12 formed in the sensing shaft 10 for injecting nitrogen into the sensing shaft 10 and an inlet port 22 connected to the inlet 13 of the nitrogen injection passage 12, And a radio detection sensor 28 coupled to the outlet 14 of the nitrogen injection passage 12 for sensing and transmitting the nitrogen pressure in the nitrogen injection passage 12. [

The nitrogen injection passage 12 is formed to have a plurality of passages in the sensing shaft 10 and each of the plurality of passages is formed to have a separate space so that the inlet 13 and the outlet 14 are separately provided Respectively.

An input port 22 and a check valve 24 are provided in the inlet 13 of the plurality of nitrogen injection passages 12 and a plurality of nitrogen detection sensors 28 Respectively. The display unit 30 is provided with display windows 32 for separately displaying the pneumatic pressures sensed by the plurality of nitrogen injection passages 12. [

In the present invention, the pneumatic pressures in the plurality of nitrogen injection passages 12 are respectively measured by the respective wireless sensors 28 and transmitted to the display unit 30 so as to be individually displayed on the respective display windows 32 Therefore, it is possible to confirm the change in the pressure for each of the plurality of nitrogen injection passages 12.

Therefore, it is possible to easily monitor at which portion of the sensing shaft 10 a crack occurs, a plurality of crack regions, and a degree of cracking by the display unit 30, Can be diagnosed.

7 is a partially cutaway perspective view showing a fourth embodiment of the sensing shaft 10 of the present invention.

A nitrogen injection passage 12 formed in the sensing shaft 10 so as to inject nitrogen into the sensing shaft 10; a nitrogen injection passage 12 formed in the sensing shaft 10; An input port 22 coupled to the inlet 13 of the nitrogen injection passage 12 and a wireless sensor 28 coupled to the outlet 14 of the nitrogen injection passage 12 for sensing and transmitting the nitrogen pressure in the nitrogen injection passage 12. [ .

Here, the nitrogen injection passage 12 is formed so as to extend from one end of the sensing shaft 10 to the other end along the longitudinal direction, and a male screw portion 20 is formed at one end of the sensing shaft 10.

A nitrogen induction cap 34 having a female screw portion 36 to be fastened to the male screw portion 20 of the sensing shaft 10 is provided. An air chamber 38 is formed in the nitrogen induction cap 34 so that a plurality of nitrogen injection passages 12 are connected to each other.

In the present invention, when the nitrogen injection passages 12 are formed in the sensing shaft 10 and the nitrogen induction cap 34 is fastened to the end of the sensing shaft 10, a plurality of nitrogen injection passages 12 are connected at the same time .

Therefore, the operation of connecting the nitrogen injection passage 12 is very simple, and thus the productivity of the sensing shaft 10 is greatly improved.

On the other hand, the hose 27 of the nitrogen injector 26 is formed with an inner layer formed by extruding polybutylene into the inner surface of the pressure hose formed of thermoplastic rubber. The pressure hose (27) having the inner layer can be protected by metal weaving.

According to a preferred embodiment of the present invention, the coating thickness of the inner layer of polybutylene that is double-extruded on the inner surface of the pressure-resistant hose 27 may be 0.3 mm to 0.5 mm. If the thickness is less than 0.3 mm, the surface coating effect of the thermoplastic rubber is low and cracks may occur. If the thickness exceeds 0.5 mm, the hysteresis of the hose 27 due to the difference in hardness frequently occurs. Most preferably, polybutene-1 having a melt index (MI) of 4 g / 100 min is made to have a thickness of 0.1 mm when a hose 27 made of a thermoplastic rubber material having a hardness (Shore A) of 55 degrees is used as an outer layer. As a result, the hose 27 does not bend even with a constant bending radius of 20 mm, and it can have a curvature radius (bending radius) which is approximately equal to the curvature radius 15 mm of the EPDM hose.

The flexible pressure-resistant hose 27 having excellent durability as described above is formed by the inner layer formed by extruding polybutylene into the inner surface of the pressure-resistant hose made of a polymer compound using a conventional crosslinking agent at a constant ratio, 27 is prevented from leaking out of the surface of the material of the material of the hose 27. In addition, the hose 27 can be prevented from bending due to excellent moldability and flexibility. Particularly, in the flexible pressure hose 27 according to the present invention, the hose 27 of a double-layer structure is rapidly bended by double extrusion molding of a certain hardness, The discarding phenomenon is prevented.

The case of the display unit 30 may be made of a polypropylene resin composition. That is, the case may be molded with a polypropylene resin composition containing (A) crystalline polypropylene, (B) ethylene butyl acrylate polymer, (C) styrene type hydrogenated block copolymer and (D) inorganic filler. Therefore, in the present invention, such a case can be molded with such a polypropylene resin composition, and excellent coating adhesion and excellent impact resistance can be exhibited without applying a primer.

 (A) crystalline polypropylene

The crystalline polypropylene (A) may comprise at least one selected from a crystalline polypropylene homopolymer and a propylene-alpha olefin crystalline copolymer comprising C2 to C20 (excluding C3) alpha-olefin monomers .

Specific examples of the alpha-olefin monomers may be ethylene, 1-butene, 1-pentene, 1-hexene, 4-methylpentene, 1-heptene, 1-octene and 1-decene and preferably ethylene. The propylene-alpha olefin crystalline copolymer may be, but is not limited to, a block copolymer or a random copolymer.

The content of the polymerization unit of propylene in the propylene-alpha-olefin crystalline copolymer is not particularly limited, but is preferably 50 wt% or more in the copolymer.

The crystalline polypropylene (A) is not particularly limited in terms of stereoregularity, but any crystalline polypropylene that can achieve the object of the present invention can be used without limitation, and more specifically, C-NMR (nuclear magnetic resonance Spectrum) may be from 0.80 to 0.99, and preferably from 0.85 to 0.99.

The melt flow index (MFI, 230 ° C, 2.16 kg load) of the crystalline polypropylene (A) may be 20 to 60 g / 10 min, preferably 20 to 50 g / 10 min.

The crystalline polypropylene (A) may be contained in an amount of 44 to 57% by weight based on the resin composition. If the content of the crystalline polypropylene (A) is less than 44% by weight, the coating adhesion may be deteriorated. If the content of the crystalline polypropylene is more than 57% by weight, the flexural modulus and the coating adhesion may be lowered.

(B) Ethylene butyl acrylate polymer

In the ethylene butyl acrylate polymer (B), butyl acrylate may be contained in an amount of 20 to 40% by weight, preferably 25 to 40% by weight, based on the polymerization unit.

The ethylene butyl acrylate polymer (B) may be contained in an amount of 9 to 21% by weight based on the polypropylene resin composition. When the content of the ethylene butyl acrylate polymer (B) is less than 9% by weight, the coating adhesion is poor, and when the content is more than 21% by weight, the flexural modulus may remarkably decrease.

The melt index (190 ° C, 2.16 kg load) of the ethylene butyl acrylate copolymer (B) may be 5 to 250 g / 10 min, and preferably 10 to 200 g / 10 min.

(C) a styrene-based hydrogenated block copolymer

(C) styrene-based hydrogenated block copolymer can further improve paint adhesion and impact resistance to the polypropylene resin composition.

The styrene-based hydrogenated block copolymer (C) is preferably a styrene-ethylene-butene-styrene block copolymer (SEBS), a styrene-ethylene-propylene- , Styrene-ethylene-isoprene-styrene block copolymer, acrylonitrile-butylene-styrene block copolymer and the like, preferably styrene-ethylene-butene-styrene block copolymer (SEBS) and Styrene-ethylene-propylene-styrene block copolymer (SEPS).

The styrene-based hydrogenated block copolymer (C) may be contained in an amount of 7 to 21% by weight, preferably 10 to 18% by weight, based on the polypropylene resin composition. When the content of the styrene-based hydrogenated block copolymer (C) is less than 7% by weight, the coating adhesion is decreased. When the content is more than 21% by weight, mechanical properties such as rigidity and coating adhesion may be lowered.

(D) Inorganic filler

The inorganic filler may be used to reinforce the rigidity of the polypropylene resin composition. The inorganic filler may be at least one selected from the group consisting of talc, barium sulfate and calcium carbonate, preferably talc.

The particle size of the talc can be determined from the grain size of 50% by weight accumulated from the particle cumulative distribution curve measured according to the laser diffraction method, and the average particle size can be 10 탆 or less, preferably 0.5 to 8 탆. If the particle diameter of the talc is out of the above range, the flexural modulus may be lowered, which is not preferable.

The talc may contain various organic titanate-based coupling agents, organic silane coupling agents, unsaturated carboxylic acids, or anhydrides thereof in order to improve the adhesiveness or dispersibility with the polymer. Grafted polyolefins, fatty acids, fatty acid metal salts, fatty acid esters, and the like.

The inorganic filler may be contained in an amount of 10 to 23% by weight, preferably 10 to 21% by weight, based on the polypropylene resin composition. If the content of the inorganic filler is less than 10% by weight, the flexural modulus may be insufficient or the coating adhesion may be deteriorated. If the content of the inorganic filler is more than 25% by weight, the impact resistance may be deteriorated.

The polypropylene resin composition according to the present invention may further contain other additional components as long as the effect of the present invention is not significantly impaired. More specifically, it is preferable to use a solvent, a phenol-based and phosphorus-based antioxidant, a hindered amine-based, a benzophenone-based, benzotriazole-based weathering deterioration inhibitor, an organic aluminum compound, A dispersant represented by metal salt of stearic acid, a coloring material such as quinacridone, titanium oxide, and carbon black, but the present invention is not limited thereto.

The polypropylene resin composition according to the present invention can be produced according to a process for producing a resin composition known in the art, for example, by mixing the components in a stirring-mixing apparatus such as a Hensel mixer, a super mixer or a tumbler mixer And the mixture is agitated-mixed for 1 to 10 minutes and can be pelletized by melting and kneading at a temperature of 180 to 230 DEG C using a mill or an extruder.

In the present invention, the case is made of a molded article made of the polypropylene resin composition, but the molded article can be produced by any molding method such as injection molding, extrusion molding, and the like, but is not limited thereto. In this case, an insulating film may be formed on the outer surface of the molded product of the polypropylene resin composition.

10: sensing axis 12: nitrogen injection passage
13: entrance 14: exit
16: connecting passage 18: closing member
20: male thread portion 22: input port
24: Check valve 26: Nitrogen injector
27: Hose 28: Wireless sensor
30: Display unit 32: Display window
34: nitrogen-inducing cap 36: female thread portion
38: Air chamber

Claims (5)

A sensing shaft 10 installed in the apparatus and serving as a rotary shaft to receive and rotate external power, a sensing shaft 10 serving as a fixed shaft for supporting the rotary body, or a supporting shaft for supporting the equipment;
A nitrogen injection passage (12) formed in the sensing shaft (10) so that nitrogen can be injected into the sensing shaft (10);
An input port 22 coupled to an inlet 13 of the nitrogen injection passage 12;
A nitrogen injector 26 for injecting nitrogen into the nitrogen injection passageway 12 through the input port 22;
A wireless sensing sensor 28 coupled to the outlet 14 of the nitrogen injection passage 12 for sensing and transmitting the nitrogen pressure in the nitrogen injection passage 12;
And a display unit (30) for receiving and displaying a signal sensed by the wireless sensor (28).
The method according to claim 1, wherein the nitrogen injection passage (12)
The plurality of passages are connected to each other by a connection passage 16 to supply nitrogen to the plurality of nitrogen injection passages 12 through one input port 22 And,
, And both ends of the penetrating connecting passage (16) are closed with a closing member (18). The method according to claim 1,
The nitrogen injection passage 12 is formed so as to have a plurality of passages in the sensing shaft 10 and each of the plurality of passages is formed to have a separate space which is separated from each other so that the inlet 13 and the outlet 14 are separately formed However,
An inlet port (22) and a check valve (24) are provided at the inlet (13) of the plurality of nitrogen injection passages (12)
Each of the plurality of nitrogen injection passages 12 is provided with a wireless sensor 28 at an outlet 14 thereof,
The display unit 30 is provided with respective display windows 32 for separately displaying the pneumatic pressure sensed by the plurality of nitrogen injection passages 12,
The air pressure in the plurality of nitrogen injection passages 12 is measured by each of the wireless sensors 28 and transmitted to the display unit 30 so as to be individually displayed on each of the display windows 32. Thus, Wherein the pressure sensor is provided so as to be able to check a pressure change in each injection passage (12).
The method according to claim 1,
The nitrogen injection passage 12 is formed to penetrate from the one end to the other end of the sensing shaft 10 in the longitudinal direction, and a male screw portion 20 is formed at one end of the sensing shaft 10;
And a nitrogen induction cap 34 having a female screw portion 36 formed to be fastened to the male screw portion 20 of the sensing shaft 10. A plurality of nitrogen injection passages 12 are formed in the nitrogen induction cap 34 And an air chamber (38) is formed so as to be connected to each other.
An injection path processing step (S10) of forming a plurality of nitrogen injection passages (12) along the longitudinal direction on the sensing shaft (10) installed in the equipment;
A connection passage processing step (S20) of penetrating the detection shaft (10) along the transverse direction so that a plurality of nitrogen injection passages (12) are connected to each other;
A closing step S30 is performed at both ends of the connecting passage 16 with a closing member 18 so that all the passages except for the inlet 13 and the outlet 14 of the nitrogen injection passage 12 form a sealed passage connected together. Wherein the sensing axis of the shaft crack detection and monitoring system is configured to detect the axis of the shaft.

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